FIELD OF THE INVENTION
The present invention relates to a test procedure for carrying out a series of measurements on a large number of identical products after they have been manufactured, as well as to a test station for carrying out the test procedure.
When products have been manufactured, in particular semiconductor products, the quality of the final product must be checked continuously in order to ensure a high product quality standard. In this case, the accuracy and the reliability of the test apparatus plays a major role. In order to identify various discrepancies in the test apparatus early, the test apparatuses are checked at specific time intervals using previously characterized reference products.
Such diagnostic procedures and calibration routines are generally carried out by hand. This not only takes an extremely long time, but is also linked to high costs, since the test apparatus cannot be used productively during the diagnostic or calibration process. In consequence, some insidious discrepancies are frequently identified too late, which can lead to costly reworking and testing of the products.
Since every individual measurement is also subject to errors, specific measurement tolerances must also be introduced during the development of the test routines. The manufacturer's details relating to the test equipment are normally taken into account in this case. These details are generally not checked, or are too complex, and this is generally inconsistent with guaranteeing that the manufactured products have a high standard of quality (fault rate&lt;1 ppm).